mkisofs example for PowerPC

SUSE Linux Enterprise Server 15 ppc64le
SUSE Linux Enterprise Server for SAP Applications 15 ppc64le
SUSE Linux Enterprise Server 12 ppc64le
SUSE Linux Enterprise Server for SAP Applications 12 ppc64le

The following is an example of steps to create a custom SLES ISO to boot on PowerPC. 
The reason, for example, if you would like to add custom kernel boot flags or an autoyast.xml file to setup autoinstall from the ISO.

Make a directory called "ISOFILES" and copy the contents of the ISO to that directory:

mkdir /tmp/isomnt/
mkdir /tmp/powerpc/ISOFILES/
mount -o loop SLE-12-SP5-Server-DVD-ppc64le-GM-DVD1.iso /tmp/isomnt/
cp -a /tmp/isomnt/* /tmp/powerpc/ISOFILES/

Then remove the /boot and /ppc directories from that location.

rm -rf /tmp/powerpc/ISOFILES/boot
rm -rf /tmp/powerpc/ISOFILES/ppc

Then from the "PowerPC" ISO, copy the directories /boot and /ppc to the top level directory:

cp -a /tmp/isomnt/boot /tmp/powerpc/
cp -a /tmp/isomnt/ppc /tmp/powerpc/

*make any custom edits or file changes you need*

Then cd to /tmp/powerpc/
The directory structure in your "/tmp/powerpc/" directory should look like this:

ls -la /tmp/powerpc/
boot/
ISOFILES/
ppc/

In the directory /tmp/powerpc/ run this mkisofs command:
SLES12:

mkisofs -v -o SLES12PPC.iso -U -chrp-boot -R -J -V SLES12PPC.001 -graft-points boot=boot ppc=ppc ISOFILES/

This should add all the SUSE ISO files to your custom ISO (SLES12PPC.iso).


SLES15:
In SLES15, the filenames were too long and we receive an error:

mkisofs: Error: ISOFILES/<snip> have the same Joliet name
mkisofs: Joliet file names differ after 75 chars
mkisofs: Try to use the option -joliet-long
mkisofs: Joliet tree sort failed.

SLES15 needs the "-joliet-long" flag:

mkisofs -v -o SLES15PPC.iso -U -chrp-boot -R -J -joliet-long -V SLES15PPC.001 -graft-points boot=boot ppc=ppc ISOFILES/

This should add all the SUSE ISO files to your custom ISO (SLES15PPC.iso).


Explanation of the mkisofs command flags are:
-o ISOFILE aka --output ISOFILE
-v verbose
-U Allow Untranslated filenames
-R Generate Rock Ridge directory information
-J Generate Joliet directory information
-volid aka -V Volume ID
-chrp-boot Add CHRP boot header
-graft-points Allow to use graft points for filenames
 

Document steps to create a working custom ISO for PowerPC users.